Mr Skeptic Posted March 8, 2010 Share Posted March 8, 2010 What does a metal vapor look like? Sodium vapor, for example? I'd imagine it would lose it's silvery aspect, but would it have a color? Link to comment Share on other sites More sharing options...
vordhosbn Posted March 8, 2010 Share Posted March 8, 2010 Well, tin-lead soldering alloys are evaporeted into pretty usual looking white smoke. Or maybe the smoke is tin/lead oxide... Link to comment Share on other sites More sharing options...
John Cuthber Posted March 8, 2010 Share Posted March 8, 2010 I believe sodium vapour is blue. It absorbs exactly the same yellow light that a sodium lamp emits. Link to comment Share on other sites More sharing options...
Horza2002 Posted March 8, 2010 Share Posted March 8, 2010 I assume that sodium is coloured because heating it past its boiling point also takes it past its first ionisation energy; so gives it its characteristic orange colour. But if thats the case, then wouldn't it be a plasma and not a gas... Link to comment Share on other sites More sharing options...
John Cuthber Posted March 8, 2010 Share Posted March 8, 2010 I'm fairly sure that it's neutral sodium atoms that give that yellow colour. Link to comment Share on other sites More sharing options...
rogerxd45 Posted March 9, 2010 Share Posted March 9, 2010 most ive seen are white whether that's the oxide or metal vapor i dont know Link to comment Share on other sites More sharing options...
Zolar V Posted March 9, 2010 Share Posted March 9, 2010 I think i have brought up this type of question before. although my question was whether or not metal could be a gas. Link to comment Share on other sites More sharing options...
Horza2002 Posted March 9, 2010 Share Posted March 9, 2010 Metals can be gases yes...its just that they have such a high boiling point that they are rarely observed in it. After some thought, I didn't mean the first ionisation energy with regards to the sodium gas colour. I actually meant that heating sodium to a gas is enough to excite the electrons to give the characterisitc colour of sodium...not the ionisation energy Link to comment Share on other sites More sharing options...
Mr Skeptic Posted March 9, 2010 Author Share Posted March 9, 2010 Good points re the glowing hot gas. I think that you'd need to shine a very bright light on it to get "its color" separated from "its glow". Mercury vapor might be an exception to this. Link to comment Share on other sites More sharing options...
John Cuthber Posted March 9, 2010 Share Posted March 9, 2010 Sodium boils IIRC at about red heat but, in a vacuum (and that's the circumstances where you would usually get sodium vapour) it will generate significant vapour at a lower temperature. A bit of web searching suggests the sodium lamps run at about 250C. That's far too cold to excite the atoms to emit visible light, so it's far too cold to promote sodium atoms to the excited state that emits the yellow "sodium light". Certainly the lamps run cool enough that , if it were not for the electric discharge inside them, they wouldn't glow visible at all. Link to comment Share on other sites More sharing options...
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